\begin{tikzpicture}

\definecolor{darkgray176}{RGB}{176,176,176}
\definecolor{steelblue31119180}{RGB}{31,119,180}

\begin{axis}[
date coordinates in=x,
tick align=outside,
tick pos=left,
x grid style={darkgray176},
xmin=2020-01-01 10:48, xmax=2020-01-02 13:12,
xtick style={color=black},
y grid style={darkgray176},
ymin=-0.2, ymax=4.2,
ytick style={color=black}
]
\path [fill=steelblue31119180]
(axis cs:18262.5,3)
--(axis cs:18262.5,1)
--(axis cs:18263.5,0)
--(axis cs:18263.5,4)
--(axis cs:18263.5,4)
--(axis cs:18262.5,3)
--cycle;

\addplot [semithick, steelblue31119180]
table [header=false,col sep=comma] {%
2020-01-01 12:00,2
2020-01-02 12:00,2
};
\end{axis}

\end{tikzpicture}
